Article feeding apparatus



Dec. 1946. F. MARTINDELL ARTICLE FEEDING APPARATUS Filed July 23-, 1943 3 Sheets-Sheet l //V VEN 701E f MAE TIA/DEL L 197' TOE/V5) F. MARTINDELL ARTICLE FEEDING APPARATUS 1 Filed July 23', 1943 v3 Sheets-Sheet 2 v1 T0 .E Wi W F Patented Dec. 10, 1946 ARTICLE FEEDING APPARATUS Frank Martindell, Western Springs, 111., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application July 23, 1943, Serial No. 495,909

7 Claims.

This invention relates to article feeding apparatus and more particularly to an apparatus for feeding parts to a welding machine.

It is an object of the present invention to provide a simple and highly accurate feeding mechanism for feeding parts to a processing machine.

In accordance with one embodiment of the invention, an apparatus is provided for feeding contact springs between a pair of welding electrodes Where short lengths of contact material may be welded to the springs. The apparatus for moving the parts to position to have the contacts welded on them comprises an indexable tab-1e under constant torsion from a torque motor drive and released to step a new contact spring to position between the welding electrodes each time a welding operation is completed. The table has a pair of micrometrically adjustable pawl mechanisms associated with it and normally urged to engage teeth formed on the table to block motion of: thertable, but operable under solenoid control in timed relation to the operation of the welding machine whereby when one pawl is in engagementwith a ratchet tooth on the table, the other pawl isreleased therefrom. The micrometric adjustment of the pawls permits a very fine adjustment over a relatively wide range of the positions to which the table will be indexed.

A clear understanding of the invention may be had by reference to the following detailed description when considered in conjunction with the accompanying drawings, wherein Fig. 1 is a plan view of an indexable contact spring-carrying table and its associated parts which effect its indexing operation;

Fig. 2 is a transverse. vertical sectional view taken substantially along the line 22 of Fig. 1 in the direction of the arrows showing some details of the welding mechanism so far as they pertain to the present invention and showing the details of construction of the drive mechanism for the indexable table, together with a superposed circuit schematic of the various control connections for the apparatus;

Fig, 3 is an enlarged detail plan section of a portion of the apparatus showing the solenoid actuated pawl and a small section of the ratchet portion of the indexable table;

- Fig. 4 is an irregular vertical sectional view taken substantially along the line 4-4 of Fig. 3 in the direction of the arrows showing further details of the pawl mechanism; and

Fig. 5 is a transverse vertical sectional view taken substantially'along'the line 5-5 of Fig. 4

in the direction of the arrows showing the details of the adjusting mechanism for the pawls.

Referring to the drawings, wherein like reference characters designate the same parts throughout the several views, particular reference first being had to Fig. 2, there is shown a portion of a weldingv apparatus of the type shown in detail in the co-pending application of Frank Martindell, Serial No. 450,409, filed July 10, 1942, now Patent No. 2,388,754, dated Nov. 13, 1945. As described in detail in the aforementioned copending application, the contact welding apparatus includes a main base plate 31 having a vertical shaft 52 extending through it for driving the contact strip feeding mechanism, designated generally by the numeral II, and the circular upper welding electrode 2| through the operation of a cam shaft 46, which is adapted to be driven by the vertical shaft 52 and carries suitable cams 45, one of which drives a lever 40 which is adapted to actuate an upper electrode supporting head 22. Other cams on the shaft 45, through the instrumentality of a link M4 and lever I43, reciprocate a cutter 28. The upper welding electrode 2| is associated with a cylindrical lower welding electrode 20 and for each cycle of operation of the welding apparatus, a contact will be welded onto a contact spring. In the apparatus disclosed in the aforesaid co-pending application, means is provided for rotatin the circular upper welding electrode 2| and the cylindrical lower welding electrode 20 to present new areas of the electrodes in juxtaposed positions for each new welding operation. These mechanisms include a driving disc 6'0 and a driving finger 61 adapted to actuate the lower electrode. The driving disc 66 is mounted upon a main drive shaft 55, which is connected by suitable gearing 53 to vertical shaft 52. The main drive shaft 55 is adapted to be driven by a motor I2 secured to the underside of the base plate 3'! and connectible to the main drive shaft 55 through a solenoid actuated clutch I 3 of any suitable type. The shaft 55 i supported in a bearing l4 fixed to the underside of the base plate 31. In a preferred form of the invention, power for operating the solenoid actuated clutch is supplied from a current source 15, through a switch I 6, which is closed in a manner to be described hereinafter, and through a manually operable switch I l in series.

Mounted on the bearing bracket i4 is a stud shaft 35 having freely rotatable thereon a driven gear I 8, which has suitably secured to it a switch cam 19,,the gear l8 and switch cam l9 being rotatable together and being held on the stud shaft 30 by a collar 23. The gear I8 is adapted to be driven by a driving gear 24 mounted upon the main drive shaft 55 and when the gear 24, which is one-half the size of the gear I8, drives the gear I8 and switch cam I9, the switch cam will, at a predetermined time in the cycle of rotation of the gear I8, alternately close the switches 25 and 26 for a purpose to be explained hereinafter. This arrangement of the gears 24 and I8 and the associated switch cam I9 is such that on alternate cycles of rotation of the shaft 55, the switch 25 will be closed and on the intermediate cycles the switch 26 will be closed.

The main base plate 3'! has mounted thereon a bearing ring 38,'which encircles the lower welding electrode 20 and is mounted eccentrically of said electrode 20. This bearing ring is shaped, as shown most clearly in Fig. 4, to receive a series of ball bearings 39 between a curved surface M on the ring 38 and a cooperating curved surface 42 formed on an upper annular bearing member 43, which, in turn; supports an annular indexable table 44. The upper bearing member 43 has a ring gear 41 formed thereon and meshing with an idler gear 48, which is freely rotatable on the upper end of a stud shaft 49 set into a bearing 50. The bearing 59 is mounted on a bracket 5|, on which there is also mounted a gear housing 54. The gear housing 54 encloses a part of the gear 48 and a driving gear 56 mounted on the end of the drive shaft 57 of an induction type torque motor 58. The motor 58 is connected in parallel with the solenoid actuated clutch I3 so that whenever power is supplied to the solenoid actuated clutch for connecting the motor I2 to the main drive shaft 55, power will also be supplied to the motor, 58; tending to operate the motor 58. An induction type torque motor is chosen for this operation since the motor will tend to run continuously, but will be stalled most of the time, and thisv particular type of motor does not overheat an appreciable amount and, therefore, will not be damaged when used in this manner.

The annular indexable table 4|] is surrounded by a housingtfi, which is broken away at the point of entrance to the housing of the gear train including the gear 48. Approximately in alignment with the stud shaft 49, there is a bracket 69 fixed. to the upper surface of the housing 68 for supporting the switch I6. This switch is one of the type, known as microswitches having a roller I which is normally held in its downward position to hold the elements of switch I6 open. The bracket 69 is so shaped that the roller I9 of switch IE will be in alignment with a series of holes II formed in the indexable table 40 in position to be covered by contact springs 12 properly positioned on the table in position to have contacts welded on them. From the foregoing, it is believed to be apparent that the roller ID will move into one of the holes II if the hole is not covered by a contact spring I2 and, accordingly, will break the circuit to both the torque motor 58 and the solenoid actuated clutch I in spite of the fact that the manually operable switch I! may be closed at that time. The upper surface of the table is provided with a series of pins 13-43 for engaging the side edges of the contact springs I2 and is also provided with pins 74-14 adapted to enter suitable apertures formed in the contact springs, thus to position the contact springs in proper position to have contacts welded on them.

Since the torque motor 58 will, whenever the switches I6 and I! are closed, supply power tending to drive the gear 56 and, consequently, to imtend to rotate in the direction shown by the arrow 75 in Fig. 1. Interposed between the lower surface of the table 44 and a shoulder I6 (Fig. 4) on the bearing member 43 is a ratchet ring 'II, which is fixed to the table 44 and the bearing member 43. A pair of pawls I8 and 79 are normally urged to engage the teeth of the ratchet ring and thus block movement of the table 44. The pawls l8 and I9 and their associated actuating mechanisms are of exactly the same construction and, accordingly; only the pawl I8 will be described in detail. This mechanism is shown most clearly in Figs. 3, 4 and 5, to which reference will now be had.

The pawl I8, as seen most clearly in Fig. 3, is provided with a tooth engaging portion 89 extending from a relatively resilient portion SI, which is of substantially U-shaped configuration, permitting some flexing thereof to take up the shock of a tooth on the ratchet ring I'I engaging the tooth engaging portion of the pawl. The re- I silient portion SI of the pawl is formed integrally with an arm 82, which is, in turn, oscillatable about a pivot pin 83. The pawl 78 has a pivot pin 84 mounted in it on which there is pivotally mounted one end of an adjustable link 85, the other end of which is pivotally attached by means of a pin 86 to a cross-shaped core member, designated generally by the numeral 81. The core member 81 is provided with arms 88, 89, 90 and SI, the arms 88 and B9 constituting guide portions positioned between guide plates 92 and 93 attached to the upper and lower surfaces of guide blocks 94' and 95. The pin 86 is set into the arm 99 and the arm 9| is normally positioned a short distance Within a coil 95, which nests between the guide blocks 94 and 95 and rests upon support blocks 91 and 98 (Fig. 4), which are, in turn, mounted on thespacer block 99. Positioned directly beneath the spacer block 99 is a mounting plate I90, to the left end of which (Fig. 4) a post IIlI is attached for threadedly receiving a cylindrical adjusting member I92. The cylindrical adjusting member I02 has a central recess I03 in which a compression spring I94 is seated and the adjusting member I02 may be locked in place by a lock nut I05 after being adjusted relative to the post IOI. The head I06 of an actuator screw III'I fits into the recess I 03 and is engaged by the spring I94. The shank of the screw I0! is threaded into the arm 9| of the core member 81 and thus the core member 81 will normally be urged to the right (Fig. 3) under the force of the spring I94 and the amount of pressure exerted by; the spring I I14 on the actuator screw I9! may be adjusted by adjusting the position of the adjusting member I92 with respect to the post II. The pawl 18 and its interlinked actuating mechanism, together with the coil 96, comprise a unitary structure mounted on a unit base I20, to which the mounting plate I00 may be attached in any suitable manner and which supports a way block I'2I having a dove-tail slot I22 formed in it for receiving a dove-tail slide I23. The dove-tail slide I2 3 may be locked in the slot I 22 by means of a locking plate l24 inserted in the dove-tail slot afterthe slide I23 has been positioned therein. As is shown most clearly in Fig. 5, the dove-tail slide I 23 has the pivot pin 83 mounted in it and thus the slide I23 supports the pawl'lB. Theposition of the pawl I8 with respect to'the unit base I20 may be adjusted by shifting the slide I23 to the right or left (Fig. 5) and, accordingly, the position of the annular'inportion degree of accuracy due to 'the construction now towbe-described.

The slide I23 is provided. with a threaded aperture I25 adapted to receive a threaded portionlzfi of an adjustment screw- I21. A second threaded I23 of the adjustment screw I2I is threaded into a'threaded aperture I23 formed in an upwardly extending portion I36 of the way block I2I. The threaded portion i23 of the adjustment screw I2I has a relatively coarse thread c'ut'into it and the threaded portion I26 has a relatively'fine thread cut in it, both of the threads having their leads in the same direction whereby,

when the adjustment screw I21 isrotated, the

screw will move bodily with respect to the way block IEI and will simultaneously move the slide I23in a direction opposite to'the direction of bodily movement of the screw I21. Thus exceedingly fine adjustments maybe made in the position of the dove-tail slide and, accordingly, the position of the pawl I8 with respect to the ratchet ring I? may be adjusted. The unit base I20 for the pawls I3 and 73 may be fixed to the main base plate in any suitable mannerand the housing 63 may be provided with suitable apertures I3I, through which the free end of the adjustment screws I2! may extend.

It will be understood that the pawl I9 is provided with a solenoid coil I32 of exactly the same construction as the solenoid coil 96 and that the two pawl actuating mechanisms and adjusting mechanisms are identical in construction. Each of the adjustment screws I21 extends through a bearing I33 individual to it and is provided with a knurled portion I34 adapted to be engaged by a retainer spring I35, whereby when the adjustment screw is set to one of its adjusted positions, the spring I35 bearing against the knurled portion I34 will prevent accidental rotation of the adjustment screw IZI.

By means of the adjustment screws I2I, the position of the pawls I3 and I9 may be adjusted over a relatively wide range, whereby the indexable table 44 may be stopped in approximately any desired position so that contact springs I2 carried thereby may have contacts welded to them in any desired location on the spring.

By reference to Fig. 2, it will be seen that the solenoid coils 9B and I32 will have current supplied to them from the source I under control of the switches 25 and 26, whereby the solenoid coils 3B and I32 will be automatically energized due to the construction of the switch cam I9, which controls the switches 25 and 23.

A complete understanding of the invention may be had by reference to the following brief description of the mode of operation of the apparatus. After a supply of contact springs I2 have been placed between the pins I3 and with the pins I4 entering the apertures in the spring I2, manually operable switch II may be closed and since the bracket '39 supporting the switch I6 is so positioned that the roller It! will be engaging an imperforate portion of the top of the table 44 when the machine is at rest, power will be supplied from the source I5 through switches I6 and I1 to the solenoid actuated clutch I3 and will initiate a cycle of operation of the shaft 55, it being assumed that a suitable source of power has been connected to the motor I2 to energize it. Since the switch 25 is closed as shown in Fig. 2 at this time, solenoid coil 96 will be energized and pawl I8 will be withdrawn from engagement with the face of the ratchet ring 11, thus permitting the '6 ratchet :ring to rotate until the pawl Ll engages one of the teeth on th ratchet wheel; Ifa complete supply of contact springs I2 has been properly positioned on thetable 44,.the :circuit to the clutch I3 will not be interrupted at :theswitch I3 and the clutch I3 will, therefore, remain 0perative and shaft will continue to rotate. As

the shaft 55 continues to rotate, the welding portion of theapparatus will operate, as described in detail in th hereinbefore identified co-pending application, and each'time the shaft 5.5 completes one revolution, a contact will be sheared oii and welded to a contact spring I2. Duetoithe gear ratio betweenthe gears IS and 24, the cam switch It will operate one or the other of .the switches 25 and 26 for each cycle of the shaft 55 these switches will be operatedalternately. Therefore, as soon as the shaft 55 completes one revolution, switch 25 will be opened to de-energize solenoid coil st and permit the pawl I3 to engage 1e sloping surface of one of the teeth on the ratchet ring 'I. Switch 28 will, at this time-be closed to'supply current to the solenoid coil I32.

.Solenoid coil I32, being energized, will remove the pawl I3 from engagement with th ratchetring II, permitting the ratchet-ring TI and table 44 secured thereto to move until the pawl I8 blocks further movement thereof. It will be understood that as soon as the switches I6 and I? are closed, power will be supplied to the induction type torque motor 53 simultaneously with the energization of the solenoid operated clutch I3 and that the torque motor will continue to exert a driving force through gears 56 and 48 to the ring gear 47 and thus all the time that the clutch I3 is energized, the motor 38 will tend to drive the table M. However, the table 44 will only move when one of the pawls I8 or I9 is removed from blocking association with the ratchet ring II. Operation of the motor 58 and clutch I3 will be interrupted any time a portion of the table 44, which should have had a contact pring 12 positioned on it arrives under the roller I0 without a contact spring in place on the table due to the roller 10 entering one of the holes II.

What is claimed is:

1. A feeding apparatus for a processing machine haVing a driving motor and an indexable table comprising a torque motor drive for said table, escapement mechanism for rendering said torque motor drive ineffective, and means driven by the processing machine motor for controlling said escapement mechanism, said escapement mechanism including a pair of alternately energizable solenoid operated pawls operable in timed relation to the processing machine.

2. In a feeding mechanism for a processing machine having a driving motor and including an indeXable table, a torque motor tending to drive said table, a ratchet on said table, solenoid operated pawls normally urged to engage said ratchet, and means driven by the driving motor of the processing machine for alternately energizing the solenoids of the solenoid actuated pawls to disengage the pawls from the ratchet.

3. In a feeding mechanism for a processin machine, the combination with means for driving the processing machine of an indexable table, a torque motor tending to drive said table, a ratchet on said table, solenoid operated pawls normally urged to engage said ratchet, means operable by the driving means for the processing machine for alternately energizin the solenoids of the solenoid actuated pawls to disengage the pawls from the ratchet, and means for adjusting 7 the effectiveposition of said pawls with respect to the ratchet.

A. In a feeding mechanism for a processing machine, the combination of a motor drive for the processing machine with an indexable table, a torque motor tending to drive said table, a ratchet on said table, solenoid operated pawls normally urged to engage said ratchet, means operable by the driving motor for the processing machine for alternately energizing the solenoids of the solenoid actuated pawls to disengage the pawls from the ratchet, and means for individually adjusting the effective position of such pawls with respect to the ratchet for adjusting the stopping positions of the indexable table.

5. In a feeding mechanism for a processing machine, the combination of a drive motor for the processing machine with an indexable table, a torque motor tending to drive said table, a ratchet on said table, solenoid operated pawls normally urged to engage said ratchet, means operable by the driving motor for the processing machine for alternately energizing the solenoids of the solenoid actuated pawls to disengage the pawls from the ratchet, and means for individually adjusting the effective position of such pawls with respect to the ratchet for adjusting the stopping positions of the indexable table, said last mentioned means including an adjustment screw having threaded portions of different pitch.

6. In a feeding mechanism, a base member, a ratchet normally urged to rotate on the base, a pawl support adjustable with respect to the base, and means for adjusting the pawl support including a bracket fixed to the base and a threaded member threadedly engaging the pawl support and base, said threaded member having portions threaded difierently to separately engage the pawl support and base.

7. In a feeding mechanism, a base member, a ratchet normally urged to rotate on the base, a pawl support adjustable with respect to the base, and means for adjusting the pawl support including a bracket fixed to the base and a threaded member threadedly engaging the pawl support and base, said threaded member having relatively coarse and fine pitched threads formed on it and having its coarse and fine threads threadedly engaging the base and pawl support,

25 respectively.

FRANK MAR'IINDEIL. 

